This invention relates to a tool for regulating the flow of ready mixed concrete down the discharge chute of a concrete mixer, and more particularly for use with a chute of the type found on trucks supplying ready mixed concrete. The invention will be described with reference to such a truck in exemplary fashion.
Concrete is generally delivered to construction sites in trucks having large mixing drums which are rotated to mix the concrete as the truck travels . This type of drum rotates about an inclined longitudinal axis with reference to the truck and has an elevated rear open end. The inside of the drum is equipped with blade structures arranged in a circumferential helix from one end to the other such that during transit, when the drum is rotated in a first direction, the concrete is mixed, and when the drum is rotated in the opposite direction the concrete is forced towards the open end of the drum where it falls from the drum into a discharge chute. This chute is adjustable so that it can be positioned to guide the concrete to a location where it is needed, for instance into a place where forms have been arranged, or alternatively into a bucket or barrow.
The chute allows concrete to slide slowly towards the lower end of the chute, and of course the chute will contain concrete when the drum stops rotating. Because the consistency of concrete varies according to the work being done, the inclination of the chute is chosen to permit controlled flow over a range of concrete mixtures. In some instances it is necessary to assist the flow and this is done usually by an operator pulling the concrete down the chute using any convenient implement such as a shovel or rake. This tends to be time consuming and not a very convenient way of cleaning the chute.
Another problem with this is that when smaller quantities of concrete are required, such as when filling a wheelbarrow, the flow of concrete must be discontinued when a full barrow is to be removed and replaced by an empty barrow. Commonly this results in lost concrete, and this is particularly a problem when an empty barrow is not availabe.
For the above reasons it is clearly desirable to be able to control the flow of concrete down a chute both by assisting the flow when the chute is to be cleaned out, and also by holding back the flow when it is necessary to discontinue flow from the chute either for a short time, or to hold the contents of the chute when the drum is stopped until it is possible to continue the process of pouring the concrete from the drum.
Accordingly, it is the object of the present invention to provide a robust inexpensive tool for moving concrete down a concrete mixer dispensing chute and also for cleaning the chute. It is a further object to provide such a tool which can also be used to retain concrete in a discharge chute when there is no demand for concrete from the chute.